Justus a



UNITED STATES PATENT OFFICE.

JUSTUS A. TRAUT, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE STANLEY RULE AND LEVEL COMPANY, OF SAME PLACE.

POCKET-RULE.

SPECIFICATION forming part of Letters Patent No. 387,570, dated August 7, 1888.

Application filed April 17, 1888. Serial No. 270,972. (No model.)

To all whom it may concern:

Be it known that I, J USTUS A. TRAUT, a citizen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented a certain new and useful Improvement in Pocket-Rules, of which the following is a specification.

My invention is in that class of rules f0 making linear measurements that are capable of being folded into compact form for convenience in carrying; and the object of my improvement is to conveniently lock the two principal members of such rules in an angular position, so that such a tool may serve the double purpose of rule and square or bevel.

In order to explain my said invention more clearly, I have annexed hereto a sheet of drawings, in which Figure 1 is a plan view of a fourfold rule embodying my invention. Fig. 2 shows the same opened to form a square. Fig. 3 shows the main hinge of said rule with the upper plate, 3, cut away to expose the middle hinge leaf. Fig. 4 is an enlarged view of the hinge end of the rule cut away on line a: m of Fig. 1.

The rulehere illustrated is identical in general construction with twenty-four-inch pocket-rules as commonly made, and therefore needs no detailed description. The several hinged members of said rule are indicated in the drawings by referenceiigures 2, 3, 4, and 5. The main or central hinge of said rule is formed of a plate, a, secured to member 2, and of corresponding plates,b b, inclosing said plate a and secured to the companion member, 3, these hinge parts being connected by a central pivot, c.

The plate a is provided with a hole, (Z, and the top plate, I), with a hole, d, said holes being so located relative to each other that when the members 2 3 of the rule are opened at a right angle, as in Fig. 2, these holes are coincident. In order to lock said parts to gether and thus form a square, I have provided in the free end of the member 5 a pin, e, which, as said member is folded against its companion, 3, enters holes d d and serves as a dowel, as will be understood by referring to the drawings. That portion of the hingeplate a between hole d and the point where pin e rests when the rule is folded I form as a curved gradually-inclined plane, f. \Vhen the rule is completely folded, the end of pin 6 is at the base of said incline; but when sections 2 3 are swung open said pin gradually rises until it reaches and enters hole (I. By varying the location of hole (I the rule may be locked at other degrees of inclination, or a series of holes may be provided and the rule utilized as a bevel.

After having used my described device as a square it may be returned to its folded posi tion or extended for further use as a rule by simply withdrawing pin a from the holes 01 d. The addition of such a locking device does not interfere with the perfect working of the rule and does not add materially to the cost of construction.

Having described my invention, I claim A four-fold rule having one leaf of its main hinge formed with a curved inclined way terminating with a hole, (I, as set forth, a companion hinge-heat having a hole, d, that may be brought into coincidence with said hole d, and a dowel-pin carried by the folding-rule section 5, adapted to engage said holes, substantially as and for the purpose specified.

JUSTUS A. TRAUT.

Witnesses:

HENRY S. WALTER, H. O. HINE. 

